Pain
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Randomized Controlled Trial Clinical Trial
Neuropsychological effects of methylphenidate in patients receiving a continuous infusion of narcotics for cancer pain.
Twenty consecutive patients with cancer pain receiving a continuous subcutaneous infusion of narcotics were admitted to a double-blind, crossover trial designed to assess the effects of methylphenidate on neuropsychological functions. After a baseline assessment, patients were randomized to receive methylphenidate orally at 08.00 h for 2 consecutive days or placebo. During day 3, a crossover took place and patients received the alternate treatment for 2 more days. ⋯ After completion of the trial, methylphenidate was chosen blindly by the patient and investigator in 13 and 14 cases, placebo in 3 and 2 cases, a "no choice" in 3 and 3 cases, respectively (P less than 0.01). Our results suggest that methylphenidate is capable of improving cognitive function in patients receiving high doses of opiates subcutaneously. More research is necessary in order to determine the duration of cognitive improvement after each dose of methylphenidate as well as the best type and dose of amphetamine.
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Randomized Controlled Trial Clinical Trial
Hypnosis or cognitive behavioral training for the reduction of pain and nausea during cancer treatment: a controlled clinical trial.
Few controlled clinical trials have tested the efficacy of psychological techniques for reducing cancer pain or post-chemotherapy nausea and emesis. In this study, 67 bone marrow transplant patients with hematological malignancies were randomly assigned to one of four groups prior to beginning transplantation conditioning: (1) hypnosis training (HYP); (2) cognitive behavioral coping skills training (CB); (3) therapist contact control (TC); or (4) treatment as usual (TAU; no treatment control). Patients completed measures of physical functioning (Sickness Impact Profile; SIP) and psychological functioning (Brief Symptom Inventory; BSI), which were used as covariates in the analyses. ⋯ Risk, SIP, and BSI pre-transplant were found to be effective predictors of inpatient physical symptoms. Nausea, emesis and opioid use did not differ significantly between the treatment groups. The cognitive behavioral intervention, as applied in this study, was not effective in reducing the symptoms measured.
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This study compared the psychometric properties of two scales designed to measure attitudes towards and beliefs about pain. The Survey of Pain Attitudes (Revised) SOPA(R) (Jensen and Karoly 1987) and the Pain Beliefs and Perceptions Inventory (PBPI) (Williams and Thorn 1989) were examined in terms of internal consistency, discriminant validity, factor structure, construct validity and sensitivity to age and gender effects. ⋯ Further work is suggested for the PBPI, as the reported factor structure was not replicated. Discussion centered around the possible reasons for this finding, with issues such as the possible orientation of different treatment facilities, the possible differences in attitudes between patients with different types of pain, and the possible influence of length of years in pain or the receipt of workers compensation payments being considered.
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We examined a pain-related syndrome, which includes mechanical allodynia and autotomy, in rats after ischemic spinal cord injury photochemically induced by laser irradiation for 5-20 min. This procedure results in an acute allodynia-like phenomenon which lasts for several days and is possibly related to dysfunction of the GABAB system in the spinal cord. In some animals this is followed by a chronic allodynia-like symptom with an onset varying between 1 week and 1.5 months after injury, expressed as a clearly painful reaction to light pressure applied to a skin area at or near the dermatome of the injured spinal segments. ⋯ The mechanism that may account for this chronic pain-related syndrome in spinally injured rats probably involves abnormalities in the central nervous system. The allodynia seen in chronic spinally injured rats was similar to some painful symptoms in patients after spinal cord injury or stroke. It is suggested that the chronic allodynia-like phenomenon may represent an animal model for studying the mechanisms of chronic central pain.
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In rats anesthetized with sodium pentobarbital, we quantitatively analyzed descending modulation from the midbrain of a nociceptive flexion withdrawal reflex and responses of associated spinal neurons. We monitored the isometric force of hind limb withdrawal elicited by noxious heat stimuli (42-54 degrees C, 10 sec) on the hind paw. In one series of experiments, single-fiber EMG electrodes recorded responses of single muscle fibers (i.e., motor units) in biceps femoris during the hind limb withdrawal, without and during electrical stimulation in the midbrain periaqueductal gray (PAG) or lateral midbrain reticular formation (LRF). ⋯ Following supplemental administration of pentobarbital (10-30 mg/kg i.v.), withdrawals and motor unit responses to heat were suppressed while dorsal horn unit responses were unchanged or enhanced. Also, in 12/42 cases, withdrawals and motor unit responses decremented markedly during the initial 3 trials of heat, while simultaneously recorded dorsal horn unit responses remained stable. These results indicate that the withdrawal reflex and associated motor units can be markedly suppressed in the absence of concomitant changes in responsiveness of dorsal horn neurons, and are discussed in terms of the neurocircuitry of spinal flexor reflexes and their descending modulation.